Murrill: Boletaceae of North America 143 



where touched. 25. C. miniato-olivaceus. 

 Stem red, yellow 

 at the top ; flesh 

 and tubes slowly 

 turning blue 

 when wounded. 26. C. bicolor. 

 Pileus yellow or brown. 

 Tubes changing to 

 blue when 

 wounded ; stem 

 glabrous. 27. C. pallidus. 



Tubes not changing 

 to blue when 

 wounded. 

 Stem furfur- 

 aceous, pale 

 yellow ; 

 tubes pale 

 yellow to 

 greenish- 



yellow. 28. C. subglabripes. 



Stem rough 

 with minute, 

 stiff, black 

 hairs ; tubes 

 brown to 



black. 29. C. scabripes. 



Pileus subtomentose ; flesh 

 usually spongy and 

 drying readily. 

 Tubes not changing 

 to blue when 

 wounded. 

 Tubes whitish, be- 

 coming yellow ; 

 mouths small, 



circular. 30. C. Roxanae. 



Tubes yellow; 

 mouths large 

 and angular, es- 

 pecially near 



the stem. 31. C. subtomentosus. 



Tubes small, yel- 

 lowish, becom- 

 ing brick-red on 

 drying or when 

 bruised ; pileus 

 large, 9-1 3 cm. 

 in diameter and 



3 cm. thick. 32. C. tomentipes. 



